Plant Upgrades
Optimising performance with revamps

Chemical plants are impressive feats of engineering – packed full of sophisticated process technologies that enable a series of complex reactions. A plant has to be running for a few years, however, before an operator can work out whether it really is working to its full potential or whether modernisation would create room for improvement. Major and sometimes even minor revamps can, for instance, increase production capacity, improve plant efficiency, or leverage the benefits of new process technologies. “Revamps bring together a whole range of engineering disciplines, adding layers of complexity that you don’t have with regular maintenance work,” explains Tomas Mehner, a highly experienced sales employee at Linde Engineering Dresden. “So you might have to replace the piping, but also modernise or renew the electrics, the steelworks, the instrumentation or other process equipment.”

Expert management of revamps

Plant operators embarking on a revamp need a partner that combines comprehensive process expertise with a strong track record in execution excellence. This is where Linde Engineering Dresden comes in with its vast plant engineering experience. “Our experts have deep knowledge of chemical and petrochemical plants,” affirms Sebastian Holz, Head of Sales and Products at Linde Engineering Dresden. “A revamp can be compared with open heart surgery: The ‘intervention’ should only last as long as is strictly necessary to minimise the length of the plant shutdown.” After all, every day of lost production results in an enormous loss of earnings for the plant operator. That is why the golden rule for Linde’s experts is to use the downtime as efficiently as possible. As well as meticulous planning and advance assembly work, extensive prefabrication of new plant components is also essential to ensure that these can be more speedily integrated into the existing complex. According to Holz: “This helps us keep the offline window as short as possible – which is exactly what our customers need.”

Polyethylene plant in Al-Jubail, Saudi Arabia.

Expanding capacity

Plant operators choose to revamp for a variety of reasons, but the decision is often linked to developments in world trade and raw materials prices. “Quite often it is purely a question of expanding capacity,” points out Mehner. “Since we know exactly what to fine-tune, in many cases we can improve the performance of an existing plant with relatively little effort and new equipment. Customers should therefore think twice before they invest in a new plant.” A detailed health check is needed to work out what can be achieved with a revamp. Every modernisation project therefore kicks off with a study. The measurements from sensors installed right throughout the plant give a good idea of the current health status. “We use a range of tools to analyse the data and look around the plant to get some hands-on insights. Our specialists also talk to the personnel on site to find out about the operating technology, capacity levels and potential problems. It is a matter of understanding where bottlenecks occur and what exactly the customer is looking to achieve,” says Mehner. Since chemical plants are dotted around the world, Linde’s experts deal with people from many nationalities. “This makes the work interesting but it is also challenging when you are faced with such diversity. No two projects or plants are the same,” comments Mehner.

Single point of accountability

Once Linde’s experts have completed their detailed survey, they know exactly what is achievable on a given budget. “It’s a bit like servicing a car: sometimes chip tuning is all you need to deliver extra revs on the road. If, however, a more powerful engine is required, then it might make more sense to trade the car in for a new model,” is how Mehner summarises the balancing act. The experts from Linde analyse the cost creep with every extra tonne produced and, in this way, arrive at the best, most profitable solution for the customer. If the customer decides to revamp, Linde’s experts can oversee the entire project from beginning to end (planning, procurement and assembly). This is a huge benefit for operators, who are then free to focus on their day-to-day operations.

Improving plant efficiency

If the customer tasks Linde Engineering with the job of increasing plant efficiency, one of first challenges lies in establishing a detailed analysis of how the energy and material flows can be optimised. Measurement data provided by the operator also comes in useful here. The Linde experts evaluate the existing consumption patterns and channel these insights into a concept to improve the plant’s performance. “Minor tweaks are often all that is needed to recover energy or to re-use materials in the process flow. And this can increase the overall efficiency of the plant,” maintains Mehner.

Teaming up for petrochemical projects

A number of successful revamps encompassing a variety of technologies (e.g. for polyethylene, monoethylene glycol, butadiene extraction, etc.) have already been completed by Linde Engineering Dresden. Most plants were based on licensed process technologies. ”Our broad experience to handle different process technologies is a key strength of Linde Engineering Dresden,” explains Mehner. “This makes it easy for us to do revamp works for technologies that we have not experienced in the past.”

Holz: “Our plan for the future is to expand our offer beyond petrochemicals to give the operators of other chemical and petrochemical plants the option of making efficiency-enabling investments.”